U.S. patent number 8,485,260 [Application Number 13/435,608] was granted by the patent office on 2013-07-16 for modular backup fluid supply system.
This patent grant is currently assigned to Transocean Offshore Deepwater Drilling. The grantee listed for this patent is Angela Donohue, Steve O'Leary, Tom Thrash. Invention is credited to Steve Donohue, Steve O'Leary, Tom Thrash.
United States Patent |
8,485,260 |
Donohue , et al. |
July 16, 2013 |
Modular backup fluid supply system
Abstract
A system and method to allow backup or alternate fluid flow
routes around malfunctioning components using removable, modular
component sets. In one exemplary embodiment, an ROV establishes a
backup hydraulic flow to a BOP function by attaching one end of a
hose to a modular valve block and the other end to an intervention
shuttle valve, thus circumventing and isolating malfunctioning
components. A compound intervention shuttle valve is provided that
comprises first and second primary inlets, first and second
secondary inlets, and an outlet. A modular valve block is provided
that comprises a directional control valve, a pilot valve, a
manifold pressure regulator, a pilot pressure regulator, stab type
hydraulic connections and an electrical wet-make connection.
Inventors: |
Donohue; Steve (Sugar Land,
TX), O'Leary; Steve (Houston, TX), Thrash; Tom
(Houston, TX) |
Applicant: |
Name |
City |
State |
Country |
Type |
O'Leary; Steve
Thrash; Tom
Donohue; Angela |
Houston
Houston
Sugar Land |
TX
TX
TX |
US
US
US |
|
|
Assignee: |
Transocean Offshore Deepwater
Drilling (Houston, TX)
|
Family
ID: |
37709372 |
Appl.
No.: |
13/435,608 |
Filed: |
March 30, 2012 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20120186820 A1 |
Jul 26, 2012 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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12814212 |
Jun 11, 2010 |
8186441 |
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11461913 |
Aug 2, 2006 |
7757772 |
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60705538 |
Aug 2, 2005 |
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Current U.S.
Class: |
166/344; 137/884;
166/341; 166/351; 166/368 |
Current CPC
Class: |
E21B
33/0355 (20130101); Y10T 137/87885 (20150401) |
Current International
Class: |
E21B
33/06 (20060101) |
Field of
Search: |
;166/341,338,339,344,347,351,368,373,381,386 ;405/191 ;137/884
;251/1.1 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Mason et at., "Surface BOP: Testing and Completing Deepwater Wells
Drilled With a Surface BOP Rig"; SPE Drilling & Completion;
Mar. 2005; 54-61. cited by applicant.
|
Primary Examiner: Buck; Matthew
Attorney, Agent or Firm: Fulbright & Jaworski LLP
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of Ser. No. 12/814,212 filed
Jun. 11, 2010 which is a divisional of U.S. Pat. No. 7,757,772
issued Jul. 20, 2012 claiming priority to provisional Application
No. 60/705,538.
Claims
What is claimed is:
1. A method, comprising: providing fluid flow to a drilling
component with one or more control components, a modular valve
block and an intervention shuttle valve; detecting a malfunctioning
control component; connecting a hose to the modular valve block and
to a secondary inlet of the intervention shuttle valve; routing
flow around the malfunctioning control component; and switching a
multiplex control system to control the modular valve block and the
drilling component.
2. The method of claim 1, in which the step of connecting the hose
comprises controlling a remote operated vehicle (ROV) to connect
the hose to the modular valve block and to the secondary inlet of
the intervention shuttle valve.
3. The method of claim 1, in which the step of routing flow around
the malfunctioning control component comprises routing flow through
the modular valve block, the hose, and the secondary inlet of the
intervention shuttle valve to the drilling component.
4. The method of claim 1, in which the step of switching the
multiplex control system comprises switching the multiplex control
system to transparently control the modular valve block and the
drilling component.
5. The method of claim 1, in which the step of providing fluid flow
to the drilling component comprises providing hydraulic fluid flow
to the drilling component.
6. The method of claim 5, in which the step of providing hydraulic
fluid flow to the drilling component comprises providing hydraulic
fluid flow to a blowout preventer (BOP) component.
7. The method of claim 1, further comprising generating the fluid
flow with at least one of an accumulator, an auxiliary supply line,
an auxiliary conduit on a marine riser, and a fluid feed from a
control pod.
8. The method of claim 1, in which the step of connecting the hose
to the modular valve block comprises connecting the hose to a valve
on the modular valve block corresponding to the drilling
component.
9. The method of claim 1, further comprising controlling a pressure
of the fluid flow through the modular valve block with a pressure
regulator.
10. The method of claim 9, further comprising activating a dump
valve on the modular valve block to decrease the pressure of the
fluid flow through the modular valve block.
11. A method, comprising: providing a first control pod, a second
control pod and at least one modular valve block, in which the
first control pod and the second control pod provide redundant
fluid flow to a drilling component; providing fluid flow routes
from each of the first control pod and the second control pod to a
plurality of intervention shuttle valves; detecting a malfunction
in the first control pod; switching the fluid flow from the first
control pod to the second control pod; coupling the modular valve
block to at least one of the intervention shuttle valves; and
switching a multiplex control system to control the at least one
modular valve block and the drilling component.
12. The method of claim 11, further comprising switching the fluid
flow from the second control pod to the first control pod.
13. The method of claim 12, further comprising providing flow
around the malfunction in the first control pod through the at
least one modular valve block and the intervention shuttle valve to
the drilling component.
14. The method of claim 11, in which the step of providing fluid
flow routes comprises providing routes from each of the first
control pod and the second control pod to a plurality of compound
intervention shuttle valves.
15. The method of claim 11, in which the step of providing fluid
flow to the drilling component comprises providing hydraulic fluid
flow to the drilling component.
16. The method of claim 15, in which the step of providing
hydraulic fluid flow to the drilling component comprises providing
hydraulic fluid flow to a blowout preventer (BOP) component.
17. The method of claim 11, in which the step of coupling the at
least one modular valve block and at least one of the intervention
shuttle valves comprises connecting a hose to the at least one
modular valve block and to at least one of the intervention shuttle
valves.
18. The method of claim 17, in which the connecting step is
performed by a remote operated vehicle (ROV).
19. The method of claim 11, further comprising controlling a
pressure of the fluid flow through the at least one modular valve
block with a pressure regulator.
20. The method of claim 19, further comprising activating a dump
valve on the at least one modular valve block to decrease the
pressure of the fluid flow through the modular valve block.
Description
TECHNICAL FIELD
The invention relates generally to a fluid supply system and
apparatus and, more particularly, to a modular backup hydraulic
fluid supply system and apparatus.
BACKGROUND OF THE INVENTION
Subsea drilling operations may experience a blow out, which is an
uncontrolled flow of formation fluids into the drilling well. Blow
outs are dangerous and costly. Blow outs can cause loss of life,
pollution, damage to drilling equipment, and loss of well
production. To prevent blowouts, blowout prevention (BOP) equipment
is required. BOP equipment typically includes a series of functions
capable of safely isolating and controlling the formation pressures
and fluids at the drilling site. BOP functions include opening and
closing hydraulically operated pipe rams, annular seals, shear rams
designed to cut the pipe, a series of remote operated valves to
allow controlled flow of drilling fluids, and well re-entry
equipment. In addition, process and condition monitoring devices
complete the BOP system. The drilling industry refers to the BOP
system in total as the BOP Stack.
The well and BOP connect to the surface drilling vessel through a
marine riser pipe, which carries formation fluids (e.g., oil, etc.)
to the surface and circulates drilling fluids. The marine riser
pipe connects to the BOP through the Lower Marine Riser Package
("LMRP"), which contains a device to connect to the BOP, an annular
seal for well control, and flow control devices to supply hydraulic
fluids for the operation of the BOP. The LMRP and the BOP are
commonly referred to collectively as simply the BOP. Many BOP
functions are hydraulically controlled, with piping attached to the
riser supplying hydraulic fluids and other well control fluids.
Typically, a central control unit allows an operator to monitor and
control the BOP functions from the surface. The central control
unit includes hydraulic control systems for controlling the various
BOP functions, each of which has various flow control components
upstream of it. An operator on the surface vessel typically
operates the flow control components and the BOP functions via an
electronic multiplex control system.
Certain drilling or environmental situations require an operator to
disconnect the LMRP from the BOP and retrieve the riser and LMRP to
the surface vessel. The BOP functions must contain the well when a
LMRP is disconnected so that formation fluids do not escape into
the environment. To increase the likelihood that a well will be
contained in an upset or disconnect condition, companies typically
include redundant systems designed to prevent loss of control if
one control component fails. Usually, companies provide redundancy
by installing two separate independent central control units to
double all critical control units. The industry refers to the two
central control units as a blue pod and a yellow pod. Only one pod
is used at a time, with the other providing backup.
While the industry designed early versions of the pods to be
retrievable in the event of component failure, later versions have
increased in size and cannot be efficiently retrieved. Further,
while prior art systems have dual redundancy, this redundancy is
often only safety redundancy but not operational redundancy,
meaning that a single component failure will require stopping
drilling operations, making the well safe, and replacing the failed
component. Stopping drilling to replace components often represents
a major out of service period and significant revenue loss for
drilling contractors and operators.
The industry needs a simple and cost effective method to provide
added redundancy and prevent unplanned stack retrievals. The
industry needs an easily retrievable system that allows continued
safe operation during component down time and integrates easily and
quickly into existing well control systems. The industry needs a
simpler, economic, and effective method of controlling subsea well
control equipment.
BRIEF SUMMARY OF THE INVENTION
In some embodiments, the present invention provides an improved
method and apparatus to provide redundancy to fluid flow components
via alternative flow routes. In some embodiments, the present
invention allows for safe and efficient bypass of faulty components
while allowing continued flow to functions or destinations. The
present invention can be integrated into various existing flow
systems or placed on entirely new flow systems to provide a layer
of efficient redundancy. In other embodiments, the present
invention relates to a stand alone control system for subsea blow
out prevention (BOP) control functions. The present invention is
particularly useful for hydraulically operated control systems and
functions in water depths of 10,000 feet or more.
In some embodiments, a fluid supply apparatus comprises a primary
fluid flow route that includes one or more primary flow control
components, an intervention shuttle valve, and a destination and a
secondary fluid flow route that bypasses the primary flow control
components, and includes a modular removable block of one or more
secondary flow control components, the intervention shuttle valve,
a selectively removable hose that connects the modular removable
block of secondary flow control components to the intervention
shuttle valve, and the destination. A remotely operated vehicle
(ROV) may deploy selectable hydraulic supply to a BOP function that
has lost conventional control. In some embodiments, the
intervention shuttle valve has an outlet that is hard piped to a
BOP function and a secondary inlet that is hard piped from a
receiver plate.
In some embodiments, the modular valve block is removable and
includes a directional control valve. More directional control
valves may be placed on modular valve block, with the number of
directional control valves corresponding to the number of BOP
functions that it may simultaneously serve. Modular valve block is
generally retrievable by an ROV, thus making repair and exchange
easy. Further, the modular nature of the valve block means that a
replacement valve block may be stored and deployed when an existing
valve block requires maintenance or service. Many other components
may be placed on the modular valve block, including pilot valves,
and pressure regulators accumulators. Pilot valves may be hydraulic
pilots or solenoid operated.
In some embodiments, the modular valve block connects to the BOP
stack via pressure balanced stab connections, and in embodiments
requiring electrical connection, via electrical wet-make
connection. In some embodiments, the modular valve block mounts
onto a modular block receiver that is fixably attached to BOP
stack. Preferably, the modular block receiver is universal so that
many different modular valve blocks can connect to it. In some
embodiments, either the modular valve block or the modular block
receiver is connected to a temporary connector for receiving a hose
to connect the modular valve block to an intervention shuttle
valve.
In some embodiments, the intervention shuttle valve comprises a
housing having a generally cylindrical cavity, a primary inlet
entering the side of the housing, a secondary inlet entering an end
of the housing, a spool-type shuttle having a detent means, and an
outlet exiting a side of the housing. In some embodiments, the
outlet is hard piped to a destination, and the primary inlet is
hard piped a primary fluid source. During normal flow, the shuttle
is in the normal flow position and fluid enters the primary inlet
and flows around the shuttle stem and out of the outlet. The
shuttle design seals fluid from traveling into other areas. When
backup flow is introduced into secondary inlet, the fluid forces
the shuttle to the actuated position, isolating the primary inlet
and allowing flow only from the secondary inlet.
In some embodiments a compound intervention shuttle valve comprises
two intervention shuttle valves whose outlets are attached to the
inlets of a gate shuttle valve. Thus, the compound intervention
shuttle valve comprises two primary inlets, two secondary inlets,
and an outlet. The gate shuttle valve is similar to the
intervention shuttle valve in that it has a shuttle that shifts to
allow flow from one inlet and to isolate flow from the other inlet,
but generally has a different shuttle design.
In some embodiments, a BOP hydraulic control system includes a blue
central control pod, a yellow central control pod, and at least one
modular valve block associated with each pod to provide universal
backup for all control pod components. The modular valve blocks
have an outlet that attaches to a hose via a temporary connection,
and the other end of the hose attaches to any one of a number of
intervention shuttle valves, each associated with a BOP function.
Thus, each modular valve block provides redundancy for at least one
BOP function.
In another embodiment, the invention comprises a stand alone subsea
control system, modular in construction and providing retrievable,
local, and independent control of a plurality of hydraulic
components commonly employed on subsea BOP systems. Such a system
eliminates the need for separate control pods. Other embodiments
allow independent ROV intervention using an emergency hydraulic
line routed from the surface to an ISV in the case of catastrophic
system control failure of all BOP functions.
Independent and/or redundant control over BOP functions reduces
downtime and increases safety. Furthermore, a control system having
easily retrievable components allows fast and easy maintenance and
replacement. The present invention, in some embodiments is
compatible with a multitude of established systems and provides
inexpensive redundancy for BOP system components. In another
embodiment of the invention, control over the modular block valves
is transparently integrated into an existing multiplex control
system, allowing an operator to control the modular valve block
using the existing control system.
The foregoing has outlined rather broadly the features and
technical advantages of the present invention in order that the
detailed description of the invention that follows may be better
understood. Additional features and advantages of the invention
will be described hereinafter which form the subject of the claims
of the invention. It should be appreciated by those skilled in the
art that the conception and specific embodiment disclosed may be
readily utilized as a basis for modifying or designing other
structures for carrying out the same purposes of the present
invention. It should also be realized by those skilled in the art
that such equivalent constructions do not depart from the spirit
and scope of the invention as set forth in the appended claims. The
novel features which are believed to be characteristic of the
invention, both as to its organization and method of operation,
together with further objects and advantages will be better
understood from the following description when considered in
connection with the accompanying figures. It is to be expressly
understood, however, that each of the figures is provided for the
purpose of illustration and description only and is not intended as
a definition of the limits of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention,
reference is now made to the following descriptions taken in
conjunction with the accompanying drawings, in which:
FIG. 1 is a schematic diagram of a subsea control module
representing one embodiment of the present invention;
FIG. 2 is a schematic view of a deep sea drilling operation
incorporating an embodiment of the present invention;
FIG. 3 is a side view of a BOP apparatus incorporating an
embodiment of the present invention;
FIG. 4A is a schematic diagram of a modular valve block according
to an embodiment of the present invention.
FIG. 4B perspective view of a modular valve block according to an
embodiment of the present invention.
FIGS. 5A and B are cross sectional side views of an intervention
shuttle valve according to embodiments of the present
invention.
FIG. 6 is a cross sectional side view of a compound intervention
shuttle valve according to an embodiment of the present
invention.
FIG. 7 is a schematic diagram of a BOP hydraulic control system
incorporating an embodiment of the present invention.
FIG. 8 is a schematic diagram of a BOP hydraulic control system
incorporating an embodiment of the present invention.
FIGS. 9A and B are flow charts showing embodiments of methods of
using the present invention.
DETAILED DESCRIPTION OF THE INVENTION
As used herein, the use of the word "a" or "an" when used in
conjunction with the term "comprising" (or the synonymous "having")
in the claims and/or the specification may mean "one," but it is
also consistent with the meaning of "one or more," "at least one,"
and "one or more than one." In addition, as used herein, the phrase
"connected to" means joined to or placed into communication with,
either directly or through intermediate components.
Referring to FIG. 1, one embodiment of the present invention
comprises redundant fluid supply apparatus 10, comprising primary
fluid flow route 11 and secondary fluid flow route 12. Primary
fluid flow route 11 begins at fluid source 13 and continues through
primary flow control components 14 and 15, through primary inlet
100 of intervention shuttle valve 16 and to destination 17.
Secondary fluid flow route 12 begins at either fluid source 13 or
alternate fluid source 102 and continues through modular valve
block 18, through selectively removable hose 19, through secondary
inlet 101 of intervention shuttle valve 16, and to destination
17.
Although FIG. 1 shows two primary flow components 14 and 15, there
may be any number of components. Primary flow components 14 and 15
may comprise any component in a fluid flow system, such as, but not
limited to, valves, pipes, hoses, seals, connections, and
instrumentation. Modular valve block 18 may comprise any modular,
removable flow control components, at least one of which should
compensate for the bypassed fluid components 14 and 15. Although
described in more detail below, intervention shuttle valve 16
accepts fluid through either primary inlet 100 secondary inlet 101.
When flow is through secondary inlet 101, components upstream of
primary inlet 100 are isolated and bypassed, but fluid continues to
flow to destination 17 via secondary fluid flow route 12.
Hose 19 connects to modular valve block 18 via temporary connection
103 and to secondary inlet 101 of intervention shuttle valve 16 via
temporary connection 104. In some embodiments, temporary connection
103 attaches directly to modular valve block 18, while in other
embodiments piping and other equipment exists between them.
Similarly, in some embodiments temporary connection 104 attaches
directly to secondary inlet 101, while in other embodiments piping
and other equipment exists between them.
Temporary connections 103 and 104 comprise commercially available
stab connections, such as those having an external self-aligning
hydraulic link that extends into a connection port and mates with
its hydraulic circuit. Generally, a stab connection comprises a
receiver or female portions and a stab or male portion, and either
portion may be referred to generically as a stab connection. In one
embodiment, secondary inlet 101 connects via piping to receiver
plate 105 that houses temporary connection 104 and may house other
temporary connections.
In some embodiments, fluid supply apparatus 10 comprises remote
operated vehicle (ROV) 106 that deploys hose 19 and connects it to
modular valve block 18 and secondary inlet 101 of intervention
shuttle valve 16. ROV 106 may also disconnect hose 19 and connect
and disconnect modular valve block 18. ROV 106 may be operated from
the surface by a human operator, or it may be preprogrammed to
perform specific connections or disconnections based on input from
a multiplex control system.
In some embodiments, fluid supply apparatus 10 is used to supply
hydraulic fluids to BOP components. Referring also to FIG. 2,
surface vessel 20 on water 21 connects to BOP stack 22 via marine
riser pipe 23. Marine riser pipe 23 may carry a variety of supply
lines and pipes, such as hydraulic supply lines, choke lines, kill
lines, etc. In such embodiments, fluid source 13 is generally a
main hydraulic supply line coming down marine riser pipe 23.
Alternate fluid source 102 may include, but is not limited to, an
accumulator, an auxiliary hydraulic supply line, an auxiliary
conduit on marine riser 23, or a hydraulic feed from control pod
24.
In one embodiment, control pod 24 attaches to BOP stack 22 and
modular valve block 18 attaches to control pod 24. Hose 19 connects
modular valve block 18 to BOP stack 22. Control pod 24 may be any
system used to control various BOP functions, and may include
various combinations of valves, gauges, piping, instrumentation,
accumulators, regulators, etc. Traditionally, the industry refers
to control pod 24 and its redundant counter-part control pod 25 as
a blue pod and yellow pod. Failure or malfunction of any one of the
components inside of control pod 24 that is not backed up according
to the present invention may require stopping drilling and
servicing the control pod, which costs a lot of money. However, one
embodiment of the present invention, including ROV 106, hose 19,
and modular valve block 18, allows redundancy for components inside
of control pod 24 by bypassing and isolating a malfunctioning
component and rerouting the fluid flow through modular valve block
18 and hose 19.
Referring to an embodiment of the present invention as demonstrated
in FIG. 3, control pod 24 (e.g., a blue pod) attaches to BOP stack
22 and modular valve block 18 attaches to control pod 24. In
addition, a second control pod 25 (e.g., a yellow pod) attaches to
BOP stack 22 and a second modular valve block 31 attaches to
control pod 25. In these embodiments, the destinations of the
hydraulic fluid are BOP functions. Control pods 24 and 25 provide
control to the various BOP functions, some of which are referred to
by numbers 301, 303, and 304. BOP control functions include, but
are not limited to, the opening and closing of hydraulically
operated pipe rams, annular seals, shear rams designed to cut the
pipe, a series of remote operated valves to allow controlled flow
of drilling fluids, a riser connector, and well re-entry equipment.
Control pods 24 and 25 are hard piped to the various BOP functions,
including BOP functions 301, 303, and 304, which means that if one
component in control pod 24 or 25 fails and must be repaired, the
whole control pod or the LMRP must be disconnected and the control
pod's control over BOP functions cease or are limited. As used
herein, "hard piped" or "hard piping" refers to piping and
associated connections that are permanent or not easily removed by
an ROV. In addition, for safety and regulatory reasons, a drilling
operation cannot or will not operate with only one working control
pod. Thus, a failure of one component of one pod forces a drilling
operation to stop. One embodiment of the present invention
overcomes this problem in subsea drilling by providing modular and
selectable backup control for many components in control modules 24
and/or 25.
Referring to FIG. 3, BOP functions 301, 303, and 304 connect via
hard piping to intervention shuttle valves 16, 300, and 302,
respectively. In this embodiment, intervention shuttle valve 16 is
hard piped to temporary connection 104 on receiver plate 105 via
hard piping 32. Intervention shuttle valves 300 and 302 also
connect to other temporary connection receivers on receiver plate
105 via hard piping. In addition, control pod 24 connects to
intervention shuttle valve 16 via hard piping 33. Although not
shown, control pod 24 also connects to intervention shuttle values
300 and 302. When a control component in control pod 24
malfunctions, the BOP function to which the control component
corresponds will not respond to normal commands (for instance, an
annular will not shut). After it is determined that a BOP component
is not working, ROV 106 may be directed to connect hose 19 at the
connection receiver on receiver plate 105 that is hard piped to the
nonresponsive function. In FIG. 3, ROV has connected hose 19 to
temporary connection 104, one of several temporary connections on
receiver plate 105. ROV 106 also connects hose 19 to modular valve
block 18 at temporary connection 103. In other embodiments, ROV 106
connects hose 19 to modular valve block 18 first and then to
intervention shuttle valve 16. In either scenario, the
malfunctioning control component of control pod 24 is bypassed, and
hydraulic fluid flows through a secondary route that includes
modular valve block 18, hose 19, and intervention shuttle valve 16.
The BOP function will now work properly, avoiding downtime.
In some embodiments, modular valve block 18 is designed to be
robust in that it is capable of servicing several different BOP
functions, each of which is selected by plugging hose 19 into the
particular intervention shuttle valve associated with the BOP
function experiencing control problems. The components on modular
valve block 18, described in detail below, may provide redundancy
for numerous components in control pod 24 and/or 25, making modular
valve block generally universal and monetarily efficient. Even
before a component failure arises, hose 19 may be connected to
modular valve block 18 and a particular connection on receiver
plate 105 to anticipate a malfunction of a particular component. Of
course, if at a later time a different component fails than the one
anticipated, ROV 106 can disconnect hose 19 from the first
connection on receiver plate 105 and connect it to a different
connection (the one corresponding to the malfunctioning BOP
function) to allow backup control.
Modular Valve Block
FIGS. 4A and B demonstrate one embodiment of modular valve block
18, which includes directional control valves 40 and 42 and pilot
valves 41 and 43. Although two sets of valves and pilot valves are
shown, any number of valves may be placed on the modular valve
block 18. The number of directional control valves corresponds to
the number of BOP functions that modular valve block 18 may
simultaneously serve. However, modular valve block 18 in most cases
is small enough to be retrievable by ROV 106. In some embodiments,
modular valve block 18 comprises manifold pressure regulator 45 to
control the hydraulic fluid supply pressure to systems components
downstream of directional control valves 40 and 42, and pilot
pressure regulator 46 to control pressure available to the pilot
system. In some embodiments, pilot pressure regulator 46 is
configured to also provide back feed hydraulic pressure to control
pod 24.
In some embodiments, modular valve block 18 comprises pressure
accumulator 44 to avoid any pressure loss when shifting pilot
valves 41 and 43, and accumulator dump valve 47 to allow venting of
accumulator 44 as required during normal operations. In some
embodiments, pilot valves 41 and 43, pressure accumulator 44,
manifold pressure regulator 45, and pilot pressure regulator 46 are
not housed on modular valve block 18, but rather are placed
upstream or are not required. While many BOP components require
hydraulic fluid at the same pressure, in embodiments where modular
valve block 18 is to be generically able to supply hydraulic fluid
to different BOP components at different pressures (such as an
annular compared to a shear ram), manifold pressure regulator 45 is
advantageous. Various combinations of valves, pilots, regulators,
accumulators, and other control components are possible, and in
some embodiments, pilot valves 41 and 43 are solenoid operated
pilot valves, while in other embodiments, they are hydraulic pilot
valves. In addition, in some embodiments, BOP stack 22 is connected
to a plurality of modular valve blocks, each of which may provide
backup for one or more control component.
Modular valve block 18 further comprises connections 400, 401, 402,
and 403 to connect to BOP stack 22. In some embodiments,
connections 400, 401, 402, and 403 are pressure balanced stab
connections that allow for removal and reinstallation via ROV 106.
In embodiments requiring electrical connection, connection 410 is
an electrical wet make connection to allow making and breaking of
electrical connections underwater. Referring to FIG. 4B, modular
valve block 18 mounts onto modular block receiver 48 in some
embodiments. Modular block receiver 48 is fixably attached to BOP
stack 22 and a hydraulic fluid supply is hard piped to it.
According to the embodiment in FIG. 4B, modular block receiver 48
includes receptacles 404, 405, 406, and 407 to receive connections
400, 401, 402, and 403. Receptacles 404, 405, 406, and 407 and
connections 400, 401, 402, and 403 are preferably universal so that
the present invention can be installed on any number of BOP stacks
and different modular valve blocks can attach to modular block
receiver 48.
Hydraulic supply connections 408 and 409 supply hydraulic fluid and
pilot hydraulic fluid to modular valve block 18. Any suitable
source may supply hydraulic supply connections 408 and 409, such
as, but not limited to, the main hydraulic supply, an accumulator,
an auxiliary hydraulic supply line, an auxiliary conduit on marine
riser 23, or a hydraulic feed from control pod 24. While temporary
connection 103 may be housed on modular valve block 18 directly, it
may also be housed on modular block receiver 48. In addition, one
or more additional temporary connections 411 may be included. The
number of temporary connections connected to modular valve block 18
generally will correspond to the number of directional control
valves on modular valve block 18 and will also generally dictate
how many BOP functions may be simultaneously served. Although
temporary connection 103 is shown as exiting the side of modular
block receiver 48, it may also exit at other locations on modular
block receiver 48, such as on a bottom portion, pointing vertically
in relation to the sea floor, for easy disconnect during emergency
stack pulls.
Intervention Shuttle Valve
Referring to FIGS. 5A and B, intervention shuttle valve 16
comprises housing 58, generally cylindrical cavity 500, primary
inlet 100, secondary inlet 101, generally cylindrical spool-type
shuttle 51, and outlet 50. Cavity 500 comprises a top generally
circular area 501, bottom generally circular area 502, and a side
cylindrical area 503. Housing 58 has lip 52 above top generally
circular area 503. In some embodiments, shuttle 51 comprises first
region 504 nearest to secondary inlet 101 and having a radius
substantially similar to that of cavity 500, second region 505
further from secondary inlet 101 and having a radius smaller than
that of first region 504, third region 506 further still from
secondary inlet 101 and having a radius substantially similar to
that of cavity 500, fourth region 507 furthest from secondary inlet
101 and having a radius smaller than that of third region 506, and
transition surface 56 between first region 504 and second region
505. Transition surface 56 may gradually slope between the radii of
first region 504 and second region 505, or it may be an immediate
change from the radius of first region 504 to that of second region
505 (in which case transition surface 56 is a flat surface normal
to the cylindrical side of second region 505). In some embodiments,
outlet 50 is hard piped to a destination, such as a BOP function,
primary inlet 100 is hard piped to control pod 24, and secondary
inlet 101 is hard piped to receiver plate 105. During normal flow,
which corresponds to flow along primary fluid flow route 11 of FIG.
1, shuttle 51 is in the normal flow position and fluid enters
primary inlet 100, flows around second region 505, and out outlet
50. Fluid does not flow to other areas because sealing areas 54 and
53, corresponding to first region 504 and third region 506,
respectively, prevent fluid from leaking or flowing past them.
Fluid flowing through primary inlet 100 applies a force against
transition region 56 to keep shuttle 51 balanced. Accordingly, the
shuttle value remains in the normal position.
When it is desired to switch from normal flow to backup flow, fluid
is introduced to secondary inlet 101, which applies pressure to
broad face 55 of shuttle 51. Because the surface area of broad face
55 is greater than the surface area of transition zone 56, a flow
of fluid in secondary inlet 101 at equal pressure to a fluid
entering through primary inlet 100 will force shuttle 51 into the
actuated position. FIG. 5B depicts an embodiment of intervention
shuttle valve 16 with shuttle 51 in the actuated position. During
flow in the actuated position, which corresponds to flow along
secondary flow route 12 of FIG. 1, fluid enters secondary inlet 101
and out outlet 50. Fluid does not flow beyond shuttle 51 because
sealing area 54 prevents flow. In addition, third region 506 hits
lip 52, which prevents shuttle 51 from actuating any further. Thus,
when shuttle 51 is in the actuated position, primary inlet 100 and
components upstream of it are isolated and bypassed. Shuttle 51 may
be reset at any time by supplying a fluid into bleed port 57 and
forcing shuttle in the normal position.
Referring to FIG. 6, in some embodiments, intervention shuttle
valve 16 is combined with other valves to form compound
intervention shuttle valve 60. In some embodiments, compound
intervention shuttle valve 60 comprises two intervention shuttle
valves 16 and 61, gate intervention shuttle valve 62, primary
inlets 100 and 600, secondary inlets 101 and 601, gate shuttle 64,
and outlet 65. Connector 63 connects compound intervention shuttle
valve 60 to a BOP function. The term "gate shuttle" is not mean to
be limiting to any particular type of shuttle or valve, but is only
used to distinguish it from intervention shuttle valve 16. Gate
intervention shuttle valve 62 can be any shuttle valve that will
shift to accept flow from only one side and isolate the other
side.
Tracing one possible flow route in FIG. 6, flow enters through
secondary inlet 101 of shuttle valve 16, forcing shuttle 51 into
the actuated position. Flow continues out intervention shuttle
valve 16 and into gate intervention shuttle valve 62, forcing gate
shuttle 64 to the left and allowing flow out outlet 65 and
isolating intervention shuttle valve 61. If flow through
intervention shuttle valve 16 ceased and flow was introduced into
shuttle valve 61, gate shuttle 64 would be forced to the right,
isolating shuttle valve 16. In some embodiments, compound
intervention shuttle valve 60 may be used to provide normal flow of
hydraulic fluid from either the blue pod or yellow pod (e.g.,
control pods 24 and 25 of FIG. 3) and alternative flow from modular
valve block 18 or 31 of FIG. 3. In such embodiments, compound
intervention shuttle valve 60 will be capable of routing hydraulic
fluid from four different sources to an outlet that leads to a BOP
function. In some embodiments, the housings of intervention shuttle
valves 16, 61, and 62 are made from a unitary piece of material,
while in other embodiments the housings are made from distinct
components and intervention shuttle valves 16, 61, and 62 are
fixably attached to each other such that the outlets of
intervention shuttle valves 16 and 61 flow into inlets 602 and 603
of gate intervention shuttle valve 62.
Schematic Flow Diagrams
FIG. 7 is a schematic including BOP pipe ram 700 and associated
hydraulic feed systems. Fluid source 13 comprises a main hydraulic
inlet and flows through valve 70 to either control pod 24 or
control pod 25. In one possible flow route, valve 70 routes flow to
control pod 24 and valve 703 routes flow through control components
14 and 15 to compound intervention shuttle valve 60. Referring
FIGS. 6 and 7, in one embodiment compound intervention shuttle
valve 60 has primary inlet 100 downstream of control pod 24,
primary inlet 600 downstream of control pod 25, secondary inlet 101
downstream of temporary connection 104, and secondary inlet 601
downstream of temporary connection 74. Gate shuttle 64 isolates the
inactive side of compound intervention shuttle valve 60 to allow
flow through connector 63 to a BOP function. In this example,
intervention shuttle valve 16 is in the actuated position to allow
flow from secondary inlet 101, and gate shuttle 64 isolates
intervention shuttle valve 61 and allows flow through intervention
shuttle valve 16.
Although the destination of the hydraulic fluid can include any BOP
function, FIG. 7 depicts an embodiment including two complementary
destinations: the first function, "pipe ram close" 701, is
associated with compound intervention shuttle valve 60 and opens
pipe ram 700, and the second function, "pipe ram open" 702, is
associated with compound intervention shuttle valve 78 and closes
pipe ram 700. In this example, hose 19 connects temporary
connection 103 and temporary connection 104 to route backup
hydraulic flow to intervention shuttle valve 16 of compound
intervention shuttle valve 60. Thus, control components 14 and 15
of control pod 24 that normally direct fluid to the function "pipe
ram close" 701 have been isolated and bypassed, and fluid flow is
routed through modular valve block 18, hose 19, and intervention
shuttle valve 16 of compound intervention shuttle valve 60.
In the embodiment of FIG. 7, both pipe ram open 702 and pipe ram
close 701 can be backed up for flow around control pod 24 and
control pod 25. Thus, complete redundancy of control components are
provided for both control pod 24 and control pod 25. Modular block
valve 18 includes an additional outlet for temporary connection
411, and modular valve block 77 includes temporary connections 75
and 76. Similarly, receiver plate 105 includes additional ports for
temporary connections 72, 73, and 74. As depicted, none of
temporary connections 411, 75, 76, 72, 73, or 74 has a hose
attached to it, but ROV 106 could attach a hose to those
connections as needed. In some embodiments, due to the universal
nature of modular block valves 18 and 77, ROV can attach hoses to
any or all temporary connections 103, 411, 75, and 76 and route the
hoses to any number of temporary connections that lead to other BOP
functions (not shown). In some embodiments, BOP functions such as
pipe ram open 702 and pipe ram close 701 can vent hydraulic fluid
using backward flow through compound intervention shuttle valves 60
and 78 to vent lines (not shown).
It is also possible for the intervention shuttle valve 16 to
provide emergency backup hotline flow to a BOP function in event of
total loss of hydraulic control. In such embodiments, ROV 106
carries an emergency hydraulic supply line from the surface and
connects it directly to temporary connection 104, which is
connected to secondary inlet 101 of intervention shuttle valve 16,
thus supplying hydraulic fluid in the event of other hydraulic
fluid supply failure. In this manner, hydraulic fluid can be
progressively supplied to any number of BOP functions in the event
of catastrophic system failure.
In some embodiments, an electronic multiplex control system ("MUX")
and an operator on the surface control and/or monitor BOP functions
and hydraulic supply. In a simple sense, the MUX allows an operator
to control BOP functions by the push of buttons or the like. For
example the operator closes an annular by pressing a button or
inputting an electronic command to signal the hydraulic system to
close the annular. In some embodiments, the present invention is
integrated into an existing multiplex system such that the
initiation of backup hydraulic supply can be commanded by the push
of a button. In addition, software can allow the switch between
normal flow and backup flow to be transparent in that the operator
pushes the same button to control a particular function whether
normal or backup flow used.
In another embodiment of the present invention, shown in FIG. 8,
central control pods (such as control pods 24 and 25 of FIG. 7) are
entirely removed from the BOP hydraulic supply system. In place of
central control pods, a plurality of primary, dedicated modular
valve blocks and associated intervention shuttle valves are hard
piped to the various BOP functions. By way of non-limiting example,
primary modular valve blocks 80 and 81 are typically hard piped to
compound intervention shuttle valves 60' and 78', respectively, but
may be connected via temporary connections. Primary modular valve
blocks 80 and 81 typically retrievably mount to modular receiver
plates, but may mount directly on the BOP stack. Having a plurality
of primary modular valve blocks makes repairing a malfunctioning
primary control component easier and more cost efficient because an
ROV can retrieve the particular malfunctioning primary modular
valve block instead of retrieving an entire central control pod. In
some embodiments, primary modular valve blocks are backed up with a
one or more secondary modular valve blocks, such as secondary
modular valve blocks 18' and 77', that connect to intervention
shuttle valves via one or more hoses 19'. Thus, total hydraulic
control is redundantly supplied via easily retrievable modular
valve blocks. In addition to being easily retrievable, the
plurality of modular valve blocks save money through economy of
scale because they can be mass produced.
Flow Diagrams
Referring to FIG. 9A, in one embodiment a method provides backup
fluid flow to a destination. In some embodiments, referring to box
91, an operator initiates an alternate fluid flow route, such as
when he detects a malfunctioning function and/or he needs to route
flow around a control component. In some embodiments, the fluid is
hydraulic fluid and the destination is a BOP function. Referring to
boxes 92 and 93, a ROV is deployed to connect a hose to a modular
valve block and a secondary inlet of an intervention shuttle valve.
After the hose is connected, flow is sent through the modular valve
block, hose, and secondary inlet of the intervention shuttle valve
and to the destination as shown in box 94. In some embodiments, as
shown in box 95, multiplex control of the hydraulic flow to the
function is transparently switched such that operator can control
the BOP function via the modular valve block using the same button
or input means that controlled the malfunctioning control
component.
FIG. 9B shows an embodiment of the present invention involving blue
and yellow central control pods to supply hydraulic fluids to one
or more BOP functions. In one embodiment, hydraulic fluid is
supplied by the blue pod, but a control component malfunction is
detected as shown in box 902. In some embodiments, as shown in box
903, hydraulic supply switches from the blue pod to the yellow pod,
the switch resulting from either operator input or automatic
computer initiation. Of course, in another embodiment, control
could remain in the blue pod while backup flow is initiated.
Referring to box 904, an ROV is deployed and connects a hose to
modular valve block and to the compound intervention shuttle valve
associated with the proper BOP function. In some embodiments, as
shown in box 905, multiplex control of the hydraulic flow to the
function is transparently switched such that an operator can
control the BOP function via the modular valve block using the same
button or input means that controlled the now-malfunctioning
control component. Referring to box 906, hydraulic supply may be
switched back to the blue pod, and hydraulic fluid flows around the
malfunctioning control component, through the modular valve block,
and to the BOP function, restoring hydraulic control of the BOP
function through the blue pod.
Although the present invention and its advantages have been
described in detail, it should be understood that various changes,
substitutions and alterations can be made herein without departing
from the spirit and scope of the invention as defined by the
appended claims. Moreover, the scope of the present application is
not intended to be limited to the particular embodiments of the
process, machine, manufacture, composition of matter, means,
methods and steps described in the specification. As one of
ordinary skill in the art will readily appreciate from the
disclosure of the present invention, processes, machines,
manufacture, compositions of matter, means, methods, or steps,
presently existing or later to be developed that perform
substantially the same function or achieve substantially the same
result as the corresponding embodiments described herein may be
utilized according to the present invention. Accordingly, the
appended claims are intended to include within their scope such
processes, machines, manufacture, compositions of matter, means,
methods, or steps.
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